Li'l Jo Construction Log
The Maxitrak Li'l Jo kit was purchased from Barry Bridges via the
Discover Live Steam for sale page. Barry had ordered the engine as a
mogul wheel configuration and with a 2 axle tender. From the notes that
Barry provided with the engine, there were a few issues with the parts
that were supplied. Barry kept a wonderful notebook with the
instructions and ideas that he had for finishing the engine. Barry had
only gotten as far as assembling the running gear when he sold the kit
to me. He had painted the frames flat black and the drivers were black
spokes with white rims. Because of the move to Colorado, this project
got put on the back burner until recently. I have started working on
the engine and will be updating this page as I proceed. I must also
thank Keith Manison for his extremely detailed description of building
a Maxitrak Pearl. His website has gone away, but he allowed me to make
a copy of it before it went down for the final count. I refer to it
regularly when trying to understand the instructions provided by
Maxitrak. There are a number of differences between the Pearl and the
Li'l Jo, but there is enough in common to make it very helpful.
02/16/2008
I started with an assessment of what has been done and what needed to
be done next. Barry had assembled the rolling gear and after some
lubrication, it seems to be smooth enough. I have found a few steps
that seem to have either not been done, or done out-of-order. The first
issue is with the valve gear. The crank arms are suppose to be
bracketed by cotter pins on the weight shaft to keep them in position.
Also, the swing arms are suppose to be pinned to the crank arm cross
shaft. Currently, if I rotate the running gear by hand, the cross
shafts will eventually work there way so that they hit each other. Here
is a close up of the swing arms and cross shaft.
Another issue is with the cylinders. The instructions call for the
cylinders without the valve chests to be mounted on the frame and
connected to the drive rods before the valve chest is mounted. As
received from Barry, the valve chests were already mounted. Luckily,
Barry has not used LocktiteŽ on anything yet, so it should be fairly
easy to remove the valve chests so that the assembly matches the
instructions.
Last issue (may not be and issue) is with the mounting of the foot
plates for the cab. The instructions call for the footplates to not be
mounted until assembling stage 4 step 2. Barry has already mounted
them. The boiler is made of copper and has a lug on each side of the
firebox that rests on the frame. This lug is then held in place
by a small angle plate that holds the lug to the frame. Barry has
already mounted the foot plates. So, I may need to unmount them to put
the boiler on the frame. The instructions are not clear, the diagram in
figure 15 looks like it should be mounted upside down compared to how
Keith mounted them on his Pearl. The footplates on the Li'l Jo extend
above the frame, so maybe it's okay to have the footplates mounted at
this stage.
02/17/2008
I decided to make my first real assembly step the mounting of the
saddle. The saddle is a welded sheet metal affair that has been
pre-drilled with the mounting holes that match holes in the frame. It
is held in-place by 5 nut/bolt pairs on each side. (Barry had already
painted it flat black.) The frame has a notch for the steam pipes to
the valves. The saddle has to be modified so that there is space for
the steam pipe to pass through the saddle and frame notch. I did this
by mounting the saddle to the frame and marking the location of the
frame notch on the saddle. I then removed the saddle and cut a wood
block to fit between the two sides so that it would not distort while I
was drilling the "notch hole". I then used a 1/2" bit to drill a hole
in saddle. Then I used a Dremel tool with a fiberglass cutting blade to
make hole into a slot.
After this, I test fit the boiler to see how things lined up and to
check the main steam pipe from the throttle. I will need to make a
similar notch for the steam pipe. This will wait until I am ready to
fit the boiler.
As you can see from the second picture, the main steam pipe is going to
need some re-bending to make it fit properly. I guess that is to be
expected as this kit was shipped from the UK to Arizona, then Michigan,
then Ohio, and finally Colorado. I have tried to anneal the pipes using
a simple propane torch, but I can't seem to get them hot enough to glow
red. I also tried some MAPP gas for a hotter flame, but that did not
work either. I will have to revive my Oxy/Acetylene torch to get the
heat I need.
I also had to drill out the hole for the blast pipe in the bottom of
the smokebox to 1/2" size. As shipped, the hole was closer to 3/8". I
did not take a picture of this, but the blast pipe is now a tight fit
into the smokebox.
02/24/2008
The first task for today was to add cotter pins to the swing arms. For
the moment, I have decided not to pin the crank arms to the weight
shaft ... they don't seem to need it. I discovered that I need to get a
better center punch. The drill bit wandered, but the holes are done and
the pins are in as you can see in this photo.
I had previously removed both cylinder blocks from the frame. I removed
the valve chest from the right cylinder and proceeded as stated in the
instructions. I remounted the cylinder (after removing the front cover)
and check for the length of the piston rod. The instructions call for
there to be a 1/8" gap between the connecting rod and the piston rod
when the piston is 1/8 of an inch from the front of the cylinder.
I cut the extra off (in place) with a Dremel motor tool and cut off
disk. The next step was to mount the crosshead guide and connect the
connecting rod to it. The steps here consisted of filing the sides of
the end of the connecting rod a bit so that it would fit into the
crosshead. Then, I attached the crosshead to the end of the connecting
rod using the supplied bearing rod and nut. Next, I used a piece of
threaded rod to make a stud for bolting the crosshead guide to the
cylinder. The crosshead guide was not drilled for the bolt that would
attach it to the motion bracket, so I marked it and drilled the needed
hole on the drill press. (The instructions are vague on the bolt to use
here ... I guessed.) I could not find the listed motion bracket spacers
in the kit, so I put a pair of washers in for now. Once all this was
done, the whole mechanism seems to move easily when turning the drivers.
I remounted the valve & valve chests and checked the valve drive
rod. The instructions call for the rod to be bent in an S shape to line
up with the valve rod. I ran out of time, so that will have to be left
until next time. Here is the current view of the right side ...
starting to take shape. I am hopeful that 2 more sessions will get me
to the point that I can run the chassis on air.
02/27/2008
I finished up the left-hand side to match what I did on the right. This
time, I removed the motion bracket and swung the connecting rod up so
that I could put the crosshead on the end of the rod more easily. That
save me endless time fiddling with the bearing/fastener that pins the
rod to the crosshead. When I did the right hand side, it was very
difficult getting that pin into the crosshead and rod from from between
the rod and the drivers. The finished job looks like this:
The next step is to bend the valve rods, time the valves and button up the cylinders for a test on air ... so close ...
03/02/2008
As mentioned from the last time, I needed to bend the valve rods so
that they lined up with the valve crosshead. The instructions simply
indicate that an S bend is necessary. You can see in this picture why
the bend is necessary:
I marked both valve rods 1 inch from each end with a magic marker. I
took them to my drill press vice and chucked them to the lines that I
had drawn and gently, but firmly bent them into the required shape.
Here is one mounted up after being bent to shape: (The bearing slipped
out for the picture ...)
The next step was to set the valves. The instructions (to me) are a bit
cryptic. I made my best attempt at it, but to me, it looks like there
is way too much motion in the valves. The instructions indicate that
there will be more motion in reverse than forward, but it still seems
too much. Anyway, after setting up the valves as best I could, I put
the front cylinder covers and valve covers on. I also put on the brass
cylinder head and valve covers because their attachment screws
penetrate the covers that they attach to. You have to put them on the
seal everything up. I decided to try running the chassis on air. I made
up a fitting that allowed me to attach the compressor to the steam line.
Drum roll please ... it works!!! The motion is not smooth and there
seems to be a lot of blow-by as the exhaust line has a constant stream
of air even when the mechanism is stopped. Currently, it seems to run
no slower than 20psi, but I imagine this will improve as it gets worked
in. It will self start if the pressure is high enough.
Now for the bad news, I had a lockup when running in reverse.
Basically, the eccentric strap and swing arm end up as an inverted V
instead of a regular V shape. I think the issue is that reach rod
pushes the swing arms too far forward and that allows the eccentric
strap to flop upward occasionally. The instructions call for moving the
reverser stand backward or forward to adjust this. I think I will have
to do that. Here are some pictures of the chassis in motion.
03/03/2008
After asking on the Home Shop Machinist live steam forum
(http://www.chaski.org/homemachinist/), I re-lubricated the valves and
cylinders with 32 wt motion oil that I have had for ages and ran the
chassis on air again. It seems to do better, but it is still rather
stiff. After running for ~10 minutes, I disconnected the air and found
that it was much easier to turn the drivers by hand.
I decided to look at mounting the axle pump. It mounts to a slightly
angled tab on a frame stretcher. As near as I can tell, this is not
going to work. The pictures show that to screw the pump into the frame
stretcher, the pump hits the axle. So, I could drop the axle to get the
pump installed, but if I screw it into the frame stretcher, the "T" end
of the pump will be right where the axle goes.
Hitting the axle ..
If screwed in as far as it goes until it hits the axle, the pump arm is
just about out of the throat when the eccentric strap is furthest away.
The o-ring just starting to show ...
If I did screw it in, it would be in the way of the front axle ...
